This application relates to the art of orthodontics and, more particularly, to an improved orthodontic apparatus and method. The invention is particularly applicable to the use of an improved thin veneer body orthodontic bracket and will be described with specific reference thereto. However, it will be appreciated that the invention has broader aspects and that certain features of the invention can be carried out with conventional orthodontic brackets.
It is routine to correct misalignment of teeth in a dental arch by bonding brackets to tooth facial surfaces and attaching an archwire to the brackets. The archwire exerts forces of very low magnitude on the teeth through the brackets for moving misaligned teeth to desired positions over extended periods of time. The brackets that are applied to the molars commonly have tubes in which end portions of the archwire are received. The brackets that are bonded to teeth other than molars have outwardly open slots receiving an archwire which is retained in the slots by elastic bands or by locking devices on the brackets.
In arrangements of the type described, the brackets usually are made as small as possible in an attempt to minimize their unsightly appearance. This provides a very small bonding area between a bracket and tooth, and the brackets are susceptible to detachment by failure of the bond. This problem cannot be overcome solely by the use of stronger adhesives because the adhesive must be one that permits eventual removal of the brackets without destroying tooth enamel.
Brackets that project relatively far outwardly from a tooth facial surface are prone to being dislodged by forces generated while biting and chewing food. The same problem exists with brackets that have irregular, angular or sharp geometric forms due to the presence of projections, grooves and archwire locking devices. These brackets also are subject to buildup of impacted food, plaque and calculus which cause stains, cavities and periodontal disease. Unlike the normal tooth contour that protects gum tissue by deflecting food away from the gums, brackets that have a relatively high profile and angular surfaces often deflect food into the gums in a manner that causes damage to gum tissue. Archwires that are held in place by bands or locking devices require frequent office visits to reposition the archwires relative to the orthodontic brackets as the teeth move.
Historically, archwires used with orthodontic brackets were quite rigid. The archwire was permanently deformed at selective locations for applying desired forces to certain teeth, and frequent adjustments were necessary. Even after the development of highly flexible archwires, orthodontic brackets with outwardly open slots continued to be used on all teeth except the first and second molars. Because the use of slots, bands and locking devices is taught in dental schools and has been employed with success for many years, there is a very strong mind-set in favor of continuing to use them and against making any significant changes. What is familiar usually is preferred over what is unknown. It is a misconception that bands or locking devices are necessary on individual brackets for adjustment purposes in order to obtain desired corrections.
It would be desirable to overcome the aforementioned problems, as well as others, by providing a new procedure for correcting misaligned teeth and to provide an improved orthodontic bracket for use in carrying out the procedure.